Vessel sealing instrument with cutting mechanism

ABSTRACT

An end effector assembly for use with an instrument for sealing and cutting tissue includes a pair of opposing first and second jaw members movable relative to the to grasp tissue therebetween. Each jaw member including a jaw housing and an electrically conductive surface adapted to connect to a source of electrosurgical energy such that the electrically conductive surfaces are capable of conducting electrosurgical energy through tissue held therebetween to effect a tissue seal. One of the electrically conductive surfaces including a channel defined therein and extending along a length thereof that communicates with a nozzle disposed in the jaw housing. The nozzle is configured to direct high pressure fluid from a fluid source into the channel for cutting tissue grasped between the jaw members.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 13/227,220 filed on Sep. 7, 2011, which is adivisional application of U.S. patent application Ser. No. 12/233,157filed on Sep. 18, 2008, now abandoned, the disclosures of all of whichare herein incorporated by reference in their entireties.

BACKGROUND

The present disclosure relates to a forceps used for both endoscopic andopen surgical procedures that includes a variety of electrode assembliesconfigured to allows a user to selectively treat and/or cut tissue. Moreparticularly, the present disclosure relates to a forceps that includesa pair of opposing jaw members configured to grasp tissue and allow auser to selectively treat tissue utilizing electrosurgical energy and/orallow a user cut tissue utilizing one or more mechanical orelectro-mechanical cutting mechanisms.

TECHNICAL FIELD

Open or endoscopic electrosurgical forceps utilize both mechanicalclamping action and electrical energy to effect hemostasis. Theelectrode of each opposing jaw member is charged to a different electricpotential such that when the jaw members grasp tissue, electrical energycan be selectively transferred through the tissue. A surgeon can eithercauterize, coagulate/desiccate and/or simply reduce or slow bleeding, bycontrolling the intensity, frequency and duration of the electrosurgicalenergy applied between the electrodes and through the tissue. In orderto effectively seal vessels or tissue, two predominant mechanicalparameters must be accurately controlled: the pressure applied to thetissue; and the gap distance between the electrodes.

Vessel or tissue sealing is more than “cauterization” which involves theuse of heat to destroy tissue (also called “diathermy” or“electrodiathermy”). Vessel sealing is also more than “coagulation”which is the process of desiccating tissue wherein the tissue cells areruptured and dried. “Vessel sealing” is defined as the process ofliquefying the collagen, elastin and ground substances in the tissue sothat the tissue reforms into a fused mass with significantly-reduceddemarcation between the opposing tissue structures.

Typically and particularly with respect to endoscopic electrosurgicalprocedures, once a vessel is sealed, the surgeon has to remove thesealing instrument from the operative site, substitute a new instrumentthrough the cannula and accurately sever the vessel along the newlyformed tissue seal. As can be appreciated, this additional step may beboth time consuming (particularly when sealing a significant number ofvessels) and may contribute to imprecise separation of the tissue alongthe sealing line due to the misalignment or misplacement of the severinginstrument along the center of the tissue seal.

SUMMARY

The present disclosure relates to an end effector assembly for use withan instrument for sealing and cutting tissue and includes a pair ofopposing first and second jaw members movable relative to the other froma first position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw memberscooperate to grasp tissue therebetween. Each jaw member includes a jawhousing and an electrically conductive surface adapted to connect to asource of electrosurgical energy such that the electrically conductivesurfaces are capable of conducting electrosurgical energy through tissueheld therebetween to effect a tissue seal. One (or both) of theelectrically conductive surfaces includes a channel defined therein thatextends along a length thereof that communicates with a nozzle disposedin the jaw housing. The nozzle is configured to direct high pressurefluid from a fluid source into the channel for cutting tissue graspedbetween the jaw members.

In one embodiment, the nozzle communicates with one or more fluidconduits disposed within the jaw housing that are configured to conveyhigh pressure fluid from a fluid source. One or more valves may beincluded that are configured to regulate the flow of high pressure fluidfrom the fluid source.

In another embodiment, each electrically conductive surface includes achannel defined therein that extends along a length thereof thatcommunicates with a corresponding nozzle disposed within each respectivejaw housing. The nozzle(s) may be tapered either longitudinally ortransversally depending upon a particular purpose.

The present disclosure also relates to an end effector assembly for usewith an instrument for sealing and cutting tissue and includes a pair ofopposing first and second jaw members movable relative to the other froma first position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw memberscooperate to grasp tissue therebetween. Each jaw member includes a jawhousing and an electrically conductive surface adapted to connect to asource of electrosurgical energy such that the electrically conductivesurfaces are capable of conducting electrosurgical energy through tissueheld therebetween to effect a tissue seal. An adhesive strip is disposedalong a length of one (or both) of the electrically conductive surfaces.After electrical activation of the electrically conductive surfaces toeffect a tissue seal, the adhesive strip is configured to retain aportion of the tissue seal to essentially tear the portion of the tissueseal away from remaining tissue when the tissue is removed from betweenthe jaw members. The adhesive strip may be configured to include aheat-activated adhesive.

In one embodiment, the adhesive strip includes a plurality of nozzlesdisposed in the jaw housing operatively coupled to an adhesive fluidsupply. The plurality of nozzles may be configured to communicate withone or more fluid conduits disposed within the jaw housing that conveythe adhesive fluid from an adhesive fluid supply. One or more valves maybe included that are configured to regulate the flow of adhesive fluidfrom the adhesive fluid supply. One or more of the plurality of nozzlesmay be tapered to direct the flow of the adhesive fluid onto theadhesive strip in a uniform and consistent manner to facilitateseparation of tissue. The adhesive fluid supply may include aheat-activated adhesive fluid.

The present disclosure also relates to an end effector assembly for usewith an instrument for sealing and cutting tissue and includes a pair ofopposing first and second jaw members movable relative to the other froma first position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw memberscooperate to grasp tissue therebetween. Each jaw member includes a jawhousing and an electrically conductive surface adapted to connect to asource of electrosurgical energy such that the electrically conductivesurfaces are capable of conducting electrosurgical energy through tissueheld therebetween to effect a tissue seal. A cutting mechanism with asharpened leading edge is fixed between the jaw members near a proximalend thereof. The sharpened leading edge of the cutting mechanism ispositioned to cut tissue between the jaw members upon forward movementof the jaw members along the tissue seal. A stop member may be disposedat the distal end of one of the jaw members that is dimensioned tomaintain a gap distance between the jaw members during electricalactivation of the electrically conductive surfaces.

In one embodiment, the stop member is operatively affixed to a guiderail-system disposed within one of the jaw housings that allows the jawmembers and the cutting mechanism to move forward over the stop memberto sever tissue along the tissue seal.

The present disclosure also relates to an end effector assembly for usewith an instrument for sealing and cutting tissue and includes a pair ofopposing first and second jaw members movable relative to the other froma first position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw memberscooperate to grasp tissue therebetween. Each jaw member includes a jawhousing and an electrically conductive surface adapted to connect to asource of electrosurgical energy such that the electrically conductivesurfaces are capable of conducting electrosurgical energy through tissueheld therebetween to effect a tissue seal. One or both of the jawmembers includes an elongated perforation strip that extends inwardlyfrom the electrically conductive surface thereof. The elongatedperforation strip is dimensioned to perforate the tissue upon closure ofthe jaw members against tissue and activation of the electricallyconductive surfaces to effect a tissue seal. The perforation strips oneach respective jaw member may be configured to intermesh with oneanother upon closure of the jaw members against tissue and activation ofthe electrically conductive surfaces to effect a tissue seal.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1A is a right, perspective view of an prior art endoscopic bipolarforceps having a housing, a shaft and an end effector assembly having apair of opposing jaw members affixed to a distal end thereof;

FIG. 1B is an enlarged, left perspective view of the end effectorassembly with the jaw members shown in an open configuration;

FIG. 1C is an enlarged, right side view of the end effector assembly ofFIG. 1B;

FIG. 2 is an enlarged, left perspective view of an alternate embodimentof an end effector assembly according to the present disclosure having ahigh pressure fluid nozzle disposed therein for cutting tissue;

FIG. 3A is an enlarged, left perspective view of an alternate embodimentof an end effector assembly according to the present disclosure having acentrally disposed adhesive strip for cutting tissue;

FIG. 3B is an enlarged, left, perspective view of an alternateembodiment of an end effector assembly according to the presentdisclosure having a centrally disposed adhesive strip for cutting tissuethat is operably coupled to an adhesive fluid supply;

FIG. 4A is an enlarged, side view of an alternate embodiment of an endeffector assembly according to the present disclosure having a centrallydisposed fixed cutter;

FIG. 4B is an enlarged, side view of an alternate embodiment of an endeffector assembly according to the present disclosure having a centrallydisposed fixed cutter that is configured to ride atop an isolated stopmember, the jaw members and the cutter being shown in a first retractedposition before tissue cutting;

FIG. 4C is an enlarged, side view of an alternate embodiment of an endeffector assembly according to the present disclosure having a centrallydisposed fixed cutter that is configured to ride atop an isolated stopmember, the jaw members and the cutter being shown in a second extendedposition after tissue cutting; and

FIG. 5 is an enlarged, right perspective view of an alternate embodimentof an end effector assembly according to the present disclosure having apair of opposing centrally disposed perforating strips dimensioned toperforate tissue upon closure of the jaw members against tissue.

DETAILED DESCRIPTION

Referring initially to FIGS. 1A-1C, a bipolar forceps for use inconnection with endoscopic surgical procedures is depicted. For thepurposes herein, either an endoscopic instrument or an open instrumentmay be utilized with the various electrode assemblies described herein.Obviously, different electrical and mechanical connections andconsiderations apply to each particular type of instrument, however, thenovel aspects with respect to the electrode assembly and the operatingcharacteristics associated therewith remain generally consistent withrespect to both the open or endoscopic designs.

Generally, the end effector designs depicted herein are used to cuttissue along a vessel seal. However, any one of the various designs maybe utilized to cut tissue after electrically treating tissue in adifferent fashion (e.g., coagulating or cauterizing tissue) or forsimply cutting tissue without necessarily electrically treating tissue.

Bipolar forceps 10 generally includes a housing 20, a handle assembly30, a rotating assembly 80, a switch assembly 70 and an electrodeassembly 105 having opposing jaw members 110 and 120 that mutuallycooperate to grasp, seal and divide tubular vessels and vascular tissue.More particularly, forceps 10 includes a shaft 12 that has a distal end16 dimensioned to mechanically engage the electrode assembly 100 and aproximal end 14 that mechanically engages the housing 20. The shaft 12may include one or more known mechanically engaging components that aredesigned to securely receive and engage the electrode assembly 100 suchthat the jaw members 110 and 120 are pivotable relative to one anotherto engage and grasp tissue therebetween.

The proximal end 14 of shaft 12 mechanically engages the rotatingassembly 80 to facilitate rotation of the electrode assembly 100. In thedrawings and in the descriptions which follow, the term “proximal”, asis traditional, will refer to the end of the forceps 10 which is closerto the user, while the term “distal” will refer to the end which isfurther from the user. Details relating to the mechanically cooperatingcomponents of the shaft 12 and the rotating assembly 80 are described incommonly-owned U.S. patent application Ser. No. 11/827,297 entitled“VESSEL SEALER AND DIVIDER”.

Handle assembly 30 includes a fixed handle 50 and a movable handle 40.Fixed handle 50 is integrally associated with housing 20 and handle 40is movable relative to fixed handle 50 to actuate the opposing jawmembers 110 and 120 of the electrode assembly 100 as explained in moredetail below.

As mentioned above, electrode assembly 100 is attached to the distal end16 of shaft 12 and includes the opposing jaw members 110 and 120.Movable handle 40 of handle assembly 30 imparts movement of the jawmembers 110 and 120 about a pivot 160 from an open position wherein thejaw members 110 and 120 are disposed in spaced relation relative to oneanother, to a clamping or closed position wherein the jaw members 110and 120 cooperate to grasp tissue therebetween.

Referring now to FIGS. 1B and 1C, enlarged views of an end effectorassembly 100 of a prior device are shown in an open position forapproximating tissue. Jaw members 110 and 120 are generally symmetricaland include similar component features which cooperate to permit facilerotation about pivot pin 160 to effect the sealing and dividing oftissue. As a result and unless otherwise noted, only jaw member 110 andthe operative features associated therewith are describe in detailherein but as can be appreciated, many of these features apply to jawmember 120 as well.

Jaw member 110 also includes a jaw housing 116, an insulative substrateor insulator 114 and an electrically conducive surface 112. Insulator114 is configured to securely engage the electrically conductive sealingsurface 112. This may be accomplished by stamping, by overmolding, byovermolding a stamped electrically conductive sealing plate and/or byovermolding a metal injection molded seal plate. All of thesemanufacturing techniques produce an electrode having an electricallyconductive surface 112 that is substantially surrounded by an insulatingsubstrate 114.

As mentioned above, jaw member 120 includes similar elements whichinclude: a jaw housing 126; insulator 124; and an electrically conducivesealing surface 122 that is dimensioned to securely engage the insulator124. Electrically conductive surface 122 and the insulator 124, whenassembled, form a longitudinally-oriented channel 168 definedtherethrough for reciprocation of the knife blade 205. Knife channel 168facilitates longitudinal reciprocation of the knife blade 205 along apreferred cutting plane to effectively and accurately separate thetissue along the formed tissue seal. Although not shown, jaw member 110may also include a knife channel that cooperates with knife channel 168to facilitate translation of the knife through tissue.

Jaw members 110 and 120 are electrically isolated from one another suchthat electrosurgical energy can be effectively transferred through thetissue to form a tissue seal. Electrically conductive sealing surfaces112 and 122 are also insolated from the remaining operative componentsof the end effector assembly 100 and shaft 12. A plurality of stopmembers 150 may be employed to regulate the gap distance between thesealing surfaces 112 and 122 to insure accurate, consistent and reliabletissue seals.

FIGS. 2-7 show various embodiments of different jaw memberconfigurations for selectively cutting tissue disposed between opposingjaw members. Although is some instances only one jaw member, e.g., jawmember 220, 320 and 420 is shown for the various envisioned embodiments,it should be understood that a complementary jaw member having similaroperating components may be utilized for sealing purposes or tofacilitate the cutting process.

FIG. 2 shows one embodiment of a jaw member 220 for use with the forceps10 described above. Jaw member 220 includes an insulative housing 224having an electrically conductive surface 222 disposed thereonconfigured for conducting energy to tissue. A longitudinally-orientedchannel 225 is defined within the electrically conductive surface 222and extends from a proximal end of the conductive surface 222 to adistal end thereof. Channel 225 is configured to fluidly communicatewith a nozzle 227 disposed in housing 224, which is, in turn,operatively coupled to a high pressure fluid supply 250 via conduit 235disposed through jaw member 220. Nozzle 227 is configured to redirectthe flow of fluid 228 from the high pressure fluid supply 250 andconduit 235 into the channel 225. Nozzle 227 may be geometricallyconfigured, e.g., longitudinally and/or transversally tapered, toincrease the fluid pressure and/or mold or shape the fluid 228 exitingthe nozzle 227 and channel 225 into a knife-like stream for cuttingtissue disposed between the jaw members.

Jaw member 220 cooperates with an opposing jaw member (not shown) toapproximate and seal tissue disposed therebetween. The opposing jawmember may be configured in a similar manner to direct a knife-likestream of fluid 228 into tissue to cut the tissue from an opposingdirection to facilitate the cutting process. Configuring both jawmembers in this manner may facilitate the cutting process and enhancethe overall cutting effect. The opposing fluid channel (not shown) maybe connected to the same or an independent fluid source (via a secondconduit (not shown)) depending upon a particular purpose.

In use, the user initially energizes the opposing electricallyconductive surface 222 and, for example, sealing plate 112 of FIG. 1, toeffectively seal tissue disposed between the jaw members as describedabove. Once the tissue is sealed or otherwise treated, a visual oraudible warning is typically displayed or otherwise transmitted to theuser to indicate completion of the treatment process. If desired, theuser then initiates the cutting process to separate the tissue along thetissue seal (or treatment area) by opening one or more valves 255 toinduce the high pressure fluid 228 through the conduit 235 to the nozzle227. The high pressure fluid 228 is directed into tissue 225 toeffectively sever the tissue along the longitudinally-oriented channelin the sealing surface 222.

As mentioned above, the opposing jaw member (not shown) may include asimilar configuration to enhance the cutting effect by directing highpressure fluid 228 into tissue from the opposite direction.Alternatively, the tissue may be cut without initially sealing orotherwise treating tissue.

FIG. 3A shows another embodiment of a jaw member 320 for use with theforceps 10 described above. Jaw member 320 includes an insulativehousing 324 having an electrically conductive surface 322 disposedthereon configured for conducting energy to tissue. Similar to theembodiment of the jaw member described in FIG. 2 above, jaw member 320cooperates with an opposing jaw member (not shown) to approximate andseal tissue disposed therebetween. The opposing jaw member may beconfigured in a similar manner to tear tissue from an opposing directionto facilitate the cutting process.

Jaw member 320 is configured to include a longitudinally-oriented stripof adhesive 325 disposed along sealing surface 322. Adhesive strip 325is configured to both facilitate retention of tissue during the initialtreatment of tissue (e.g., tissue sealing) and effectively grip thetissue along the center of the tissue seal to induce the tissue to teartherealong when the jaw members 320 (opposing jaw member not shown) areremoved. The adhesive strip 325 may be a heat-activated adhesive or aheat-enhanced adhesive to facilitate the tearing, i.e., cutting,process.

FIG. 3B shows a similar embodiment of a jaw member 420 for use with theforceps 10 which also utilizes an adhesive 428 to effective tear tissuealong a tissue seal. Jaw member 420 includes an insulative housing 424having an electrically conductive surface 422 disposed thereonconfigured for conducting energy to tissue. Similar to the embodimentsabove, jaw member 420 cooperates with an opposing jaw member (not shown)to approximate and seal tissue disposed therebetween. The opposing jawmember may be configured in a similar manner to tear tissue from anopposing direction to facilitate the cutting process.

A longitudinally-oriented strip 425 is defined within the electricallyconductive surface 422 and extends from a proximal end of the conductivesurface 422 to a distal end thereof. Strip 425 is configured to includea plurality of nozzles 426 disposed in housing 424, which are, in turn,operatively coupled to a fluid adhesive supply 450 via conduit 435disposed through jaw member 420. Nozzles 426 are configured to directthe flow of adhesive fluid 428 from the supply 450 and conduit 435 ontostrip 425 through corresponding nozzle ports 427 arranged longitudinallyalong strip 425. Nozzle ports 427 may be geometrically configured, e.g.,longitudinally and/or transversally tapered, to direct the flow of theadhesive 428 fluid onto the strip in a uniform and consistent manner tofacilitate separation of tissue.

Adhesive 428 is configured to both facilitate retention of tissue duringthe initial treatment of tissue (e.g., tissue sealing) and effectivelygrip the tissue along the center of the tissue seal to induce the tissueto tear therealong when the jaw members 420 (opposing jaw member notshown) are removed. The adhesive 428 may be a heat-activated adhesive ora heat-enhanced adhesive to facilitate the tearing, i.e., cutting,process. Moreover, the adhesive may be simultaneously or sequentiallyadministered during or after the creation of a tissue seal. For example,the surgeon may initially energize the jaw members to seal tissuedisposed therebetween and then open a valve to administer the adhesive428 along the strip 425. The adhesive 428 then cures and grips thetissue to promote separation thereof when the jaw members are removed.The conduit 435 may also be fluidly connected to a cleaning fluid supply(not shown) which dissolves the adhesive 428 on the strip 425 betweenuses such that the remaining tissue may be washed away after separationfrom the tissue seal.

FIG. 4A shows yet another embodiment of a cutting mechanism for forceps10 and includes end effector assembly 500 having opposing jaw members510 and 520 that are moveable relative to one another to engage tissuetherebetween to effect a tissue seal. Jaw members 510 and 520 includerespective jaw housings 516 and 524 that support electrically conductivesurface 512 and 522, respectively. Each electrically conductive surface512 and 522 is adapted to connect to an electrical energy source suchthat the electrically conductive surfaces 512 and 522 may conduct energyto tissue disposed therebetween to effectively treat, e.g., seal, tissueupon activation of the electrosurgical generator (not shown).

A cutting mechanism 540 is fixed between the jaw members 510 and 520near a proximal end thereof. The cutting mechanism 540 includes asharpened edge 545 at a distal end thereof. Once the tissue is treated,e.g., sealed, the surgeon relaxes the closing pressure of the jawmembers 510 and 520 against the tissue (e.g., by relaxing the jaw handle40 (See FIG. 1)) and simply moves the jaw members 510 and 520 forwardsuch that the sharpened edge 545 of the knife 540 severs tissue alongthe tissue seal. A stop member 550 may be disposed at the distal end ofone of the jaw members, e.g., jaw member 520, to maintain a gap distancebetween the jaw members 510 and 520 during electrical activation toeffectively seal tissue.

Alternatively and as shown in FIGS. 4B and 4C, the stop member 550 mayoperatively couple to a guide rail-system 575 that allows the jawmembers 510 and 520 and the knife 540 to move forward over the fixedstop member 550 to sever tissue along the tissue seal. The knife 540remains fixed relative to the jaw members 510 and 520 during distalmovement of the jaw members 510 and 520 over the stop member 550 (seeFIG. 4C).

FIG. 5 shows yet another embodiment of a cutting mechanism for forceps10 and includes end effector assembly 600 having opposing jaw members610 and 620 that are moveable relative to one another to engage tissuetherebetween to effect a tissue seal. Jaw members 610 and 620 includerespective jaw housings 616 and 624 that support electrically conductivesurfaces 612 and 622, respectively, that are each adapted to connect toan electrical energy source to conduct energy to tissue disposed betweenthe jaw members to effectively seal tissue.

Each jaw member 610 and 620 includes an elongated perforation strip 645a and 645 b, respectively, that extends inwardly from each respectiveelectrically conductive surface 612 and 622. The perforation strip 645 aand 645 b are aligned in general vertical registration relative to oneanother and each strip 645 a and 645 b includes a series of teeth 646 aand 646 b, respectively, that are configured to intermesh with oneanother upon closure of the jaw members 610 and 620. Alternatively, onlyone jaw member, e.g., jaw member 620, may be configured to include theperforating strip 645 b.

In use, tissue is grasped between jaw members 610 and 620 and closedunder a predetermined working pressure to effectively treat tissue,e.g., under a working pressure of about 3 kg/cm² to about 16 kg/cm² toseal tissue. The perforating strips 645 a and 645 b act to both grip thetissue for manipulation purposes and perforate the tissue along thecenter of the electrically conductive surface 612 and 622. Afterelectrosurgical activation of the electrically conductive surfaces 612and 622, the jaw members 610 and 622 are released revealing a perforatedtissue line centrally-disposed between the conductive surfaces 612 and622. The surgeon thereafter tears the perforated tissue along theperforation to separate the two tissue halves.

The perforation strips 645 a and 645 b may be insulative or electricallyconductive depending upon a particular purpose or may be made from areactive material which heats up during electrical activation tofacilitate the perforation process.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the present disclosure. For example, it is contemplated that cuttingmechanism may be dimensioned as a cutting wire or cutting blade that isselectively activatable by the surgeon to divide the tissue aftersealing. More particularly, a wire or cutting blade is mounted withinthe insulator between the jaw members and is selectively energizableupon activation of a separate switch or simultaneously with theactivation of the sealing switch.

Although the specification and drawings disclose that the electricallyconductive surfaces may be employed to initially seal tissue prior tocutting tissue in one of the many ways described herein, it is alsoenvisioned that the electrically conductive surfaces may be configuredand electrically designed to perform any known bipolar or monopolarfunction such as electrocautery, hemostasis, and/or desiccationutilizing one or both jaw members to treat the tissue. Moreover, the jawmembers in their presently described and illustrated formation may beenergized or positioned to simply cut tissue without initially treatingtissue which may prove beneficial during particular surgical procedures.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

1-17. (canceled)
 18. An end-effector assembly for use with anelectrosurgical instrument, comprising: a pair of opposing jaw members,at least one of the jaw members configured to move relative to the otherjaw member from a first position in spaced relation relative to theother jaw member to a second position wherein the jaw members cooperateto grasp tissue therebetween, at least one of the jaw members configuredto apply electrosurgical energy to the tissue grasped therebetween toeffect a tissue seal; and an elongated perforation strip disposed on atleast one of the opposed jaw members configured to perforate tissue uponclosure of the opposed jaw members against tissue.
 19. The end-effectorassembly of claim 18, wherein the elongated perforation strip iscentrally disposed on at least one of the opposed jaw members.
 20. Theend-effector assembly of claim 18, wherein the elongated perforatedstrip is further configured to facilitate manual separation of tissuealong the tissue seal after application of electrosurgical energy. 21.The end-effector assembly of claim 18, wherein the elongated perforationstrip extends inwardly from an electrically-conductive surface of the atleast one jaw member.
 22. The end-effector assembly of claim 18, whereinboth of the opposed jaw members are movable relative to one another fromthe first position to the second position.
 23. The end-effector assemblyof claim 18, wherein both of the opposed jaw members includeelectrically-conductive surfaces and are coupled to a source ofelectrosurgical energy such that the opposed jaw members are capable ofconducting electrosurgical energy through tissue held therebetween toeffect the tissue seal.
 24. The end-effector assembly of claim 18,wherein the elongated perforation strip is formed of anelectrically-conductive material.
 25. The end-effector assembly of claim18, wherein the elongated perforation strip is formed of an insulativematerial.
 26. The end-effector assembly of claim 18, wherein theelongated perforation strip is formed of a reactive material configuredto generate heat during activation of the at least one jaw members tofacilitate perforation of tissue.
 27. The end-effector assembly of claim18, wherein each of the opposed jaw members includes anelectrically-conductive surface and an elongated perforation strip thatextends inwardly from the electrically-conductive surfaces thereof. 28.The end-effector assembly of claim 27, wherein the elongated perforationstrips are configured to intermesh with one another upon closure of theopposing jaw members against tissue and activation of the electricallyconductive surfaces to effect the tissue seal.
 29. The end-effectorassembly of claim 28, wherein the elongated perforation strips include aseries of teeth configured to intermesh with one another upon closure ofthe opposing jaw members.
 30. The end-effector assembly of claim 27,wherein the elongated perforation strips are configured to align invertical registration relative to one another.
 31. The end-effectorassembly of claim 18, wherein the elongated perforation strip isconfigured to perforate tissue along a center line of an electricallyconductive surface of at least one of the jaw members.
 32. Theend-effector assembly of claim 18, wherein the opposed jaw members areconfigured to apply a closure pressure of about 3 kg/cm² to about 16kg/cm² in the second position.
 33. A method of treating tissue,comprising: grasping tissue between a pair of opposing jaw members, atleast one of the jaw members including an elongated perforation stripcentrally disposed thereon configured to perforate the tissue along aperforated tissue line; transmitting energy from an electrosurgicalenergy source to at least one of the jaw members to activate anelectrically-conductive surface thereof and conduct electrosurgicalenergy through the tissue grasped therebetween to effect a tissue seal;opening the jaw members to expose the tissue; and separating the tissuealong the perforated tissue line.
 34. The method of treating tissue ofclaim 33, further including heating a reactive material of the elongatedperforation strip during activation of the electrically-conductivesurface to facilitate perforation of tissue.
 35. The method of treatingtissue of claim 33, wherein the transmitting of electrosurgical energyto at least one of the jaw members facilitates perforating the tissuealong the perforated tissue line.
 36. The method of treating tissue ofclaim 33, wherein the elongated perforation strip perforates tissuealong the perforated tissue line upon the grasping thereof.